<template>
  <!-- 商品分类导航 -->
  <div class="type-nav">
    <div class="container">
      
      <div @mouseenter="mouseEnterTit" @mouseleave="mouseLeaveTit">
        <h2 class="all">全部商品分类</h2>
        <transition name="nav">
          <div class="sort" v-show="isShow">
            <div class="all-sort-list2" @mouseleave="crunt = -1">
              <!-- 一级列表 -->
              <div
                class="item"
                v-for="(category , index) in cateGoryList"
                :key="category.categoryId"
                :class = "crunt === index ? 'active' : '' "
                @mouseenter="throttleEnter(index)"
                @click="toSearch"
              >
                <h3>
                  <a 
                    :data-category1id = "category.categoryId"
                    :data-categoryname = "category.categoryName"
                  >{{category.categoryName}}</a>
                </h3>
                <div class="item-list clearfix">
                  <div class="subitem">
                    <!-- 二级列表 -->
                    <dl
                      class="fore"
                      v-for="child in category.categoryChild"
                      :key="child.categoryId"
                    >
                      <dt>
                        <a 
                          :data-category2id = "child.categoryId"
                          :data-categoryname = "child.categoryName"
                        >{{child.categoryName}}</a>
                      </dt>
                      <dd>
                        <!-- 三级列表 -->
                        <em v-for="item in child.categoryChild" :key="item.categoryId">
                          <a 
                            :data-category3id = "item.categoryId"
                            :data-categoryname = "item.categoryName"
                          >{{item.categoryName}}</a>
                        </em>
                      </dd>
                    </dl>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </transition>
      </div>

      <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">尚品汇超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">有趣</a>
        <a href="###">秒杀</a>
      </nav>
    </div>
  </div>
</template>

<script>
import { mapState } from "vuex";
import _ from "lodash"
export default {
  name: "NavType",
  data(){
    return{
      crunt: -1,
      isShow: false
    }
  },

  methods: {
    //1.跳转到Search页面
    toSearch(e){
      //点击的是a标签冒泡到item上触发点击事件执行函数
      if(e.target.nodeName === "A"){
        const query = {}

        const {category1id , category2id , category3id , categoryname} = e.target.dataset

        query.categoryName = categoryname

        if(category1id){
          query.category1Id = category1id
        }else if(category2id){
          query.category2Id = category2id
        }else if(category3id){
          query.category3Id = category3id
        }

        //拿到params参数合并发送
        const params = this.$route.params
        this.$router.push({
          name: "search",
          query: query,
          params: params,
        })
      }
    },

    //2.默认隐藏search页的三级列表
    isNavShow(){
      if(this.$route.path === "/home"){
        this.isShow = true
      }
    },

    //3.移入显示
    mouseEnterTit(){
      if(this.$route.path === "/home") return 
      this.isShow = true
    },

    //3.移出隐藏
    mouseLeaveTit(){
      if(this.$route.path === "/home") return 
      this.isShow = false
    }

  },

  watch:{
    //监听路径变化隐藏三级列表
    $route:{
      handler(){
        this.isShow = false
      }
    }
  },

  mounted() {
    //1.调用lodash得到节流函数就是移入事件的事件函数 向这个函数传参 里面的核心函数(museenter)可以接到参数
    this.throttleEnter = _.throttle(
      function museenter(index){
        this.crunt = index
      }
      //关闭最后一次
      , 30 , {leading: true , trailing: false}
    )

    //2.默认隐藏search页的三级列表
    this.isNavShow()

  },

  computed: {
    ...mapState("home", ["cateGoryList"]),
  },
};
</script>

<style lang="less" scoped>

//添加动画
.nav-enter,
.nav-leave-to{
  opacity: 0;
}

.nav-enter-active,
.nav-leave-active{
  transition: all 0.3s linear;
}

.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }

          &.active {
            background-color: aqua;
            .item-list {
              display: block;
            }
          }
        }
      }
    }
  }
}
</style>